Enable reportPossiblyNonexistentArrayOffset (#245)

Author: janedbal

README.md

@@ -756,6 +756,8 @@ parameters:
     checkMissingCallableSignature: true                       # https://phpstan.org/config-reference#vague-typehints
     checkTooWideReturnTypesInProtectedAndPublicMethods: true  # https://phpstan.org/config-reference#checktoowidereturntypesinprotectedandpublicmethods
     reportAnyTypeWideningInVarTag: true                       # https://phpstan.org/config-reference#reportanytypewideninginvartag
+    reportPossiblyNonexistentConstantArrayOffset: true        # https://phpstan.org/config-reference#reportpossiblynonexistentconstantarrayoffset
+    reportPossiblyNonexistentGeneralArrayOffset: true         # https://phpstan.org/config-reference#reportpossiblynonexistentgeneralarrayoffset
 ```
 
 ## Contributing

phpstan.neon.dist

@@ -21,6 +21,8 @@ parameters:
     checkImplicitMixed: true
     checkTooWideReturnTypesInProtectedAndPublicMethods: true
     reportAnyTypeWideningInVarTag: true
+    reportPossiblyNonexistentConstantArrayOffset: true
+    reportPossiblyNonexistentGeneralArrayOffset: true
     exceptions:
         check:
             missingCheckedExceptionInThrows: true

src/Rule/AllowComparingOnlyComparableTypesRule.php

@@ -133,7 +133,7 @@ private function isComparableTogether(Type $leftType, Type $rightType): bool
                     }
 
                     for ($i = 0; $i < count($leftValueTypes); $i++) {
-                        if (!$this->isComparableTogether($leftValueTypes[$i], $rightValueTypes[$i])) {
+                        if (!$this->isComparableTogether($leftValueTypes[$i], $rightValueTypes[$i])) { // @phpstan-ignore offsetAccess.notFound, offsetAccess.notFound
                             return false;
                         }
                     }

src/Rule/EnforceEnumMatchRule.php

@@ -14,6 +14,7 @@
 use function array_map;
 use function array_merge;
 use function array_unique;
+use function array_values;
 use function count;
 
 /**
@@ -47,12 +48,12 @@ public function processNode(Node $node, Scope $scope): array
         $rightType = $scope->getType($node->right);
 
         if ($leftType->isEnum()->yes() && $rightType->isEnum()->yes()) {
-            $enumCases = array_unique(
+            $enumCases = array_values(array_unique(
                 array_merge(
                     array_map(static fn (EnumCaseObjectType $type) => "{$type->getClassName()}::{$type->getEnumCaseName()}", $leftType->getEnumCases()),
                     array_map(static fn (EnumCaseObjectType $type) => "{$type->getClassName()}::{$type->getEnumCaseName()}", $rightType->getEnumCases()),
                 ),
-            );
+            ));
 
             if (count($enumCases) !== 1) {
                 return []; // do not report nonsense comparison

src/Rule/EnforceIteratorToArrayPreserveKeysRule.php

@@ -9,6 +9,7 @@
 use PHPStan\Rules\IdentifierRuleError;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
+use function array_values;
 use function count;
 
 /**
@@ -36,15 +37,17 @@ public function processNode(Node $node, Scope $scope): array
             return [];
         }
 
-        if (count($node->getArgs()) >= 2) {
+        $args = array_values($node->getArgs());
+
+        if (count($args) >= 2) {
             return [];
         }
 
-        if (count($node->getArgs()) === 0) {
+        if (count($args) === 0) {
             return [];
         }
 
-        if ($node->getArgs()[0]->unpack) {
+        if ($args[0]->unpack) {
             return []; // not trying to analyse what is being unpacked as this is very non-standard approach here
         }
 

src/Rule/ForbidCheckedExceptionInCallableRule.php

@@ -392,7 +392,11 @@ private function isAllowedCheckedExceptionCallable(
 
         foreach ($caller->getObjectClassReflections() as $callerReflection) {
             foreach ($this->callablesAllowingCheckedExceptions as $immediateCallerAndMethod => $indexes) {
-                [$callerClass, $methodName] = explode('::', $immediateCallerAndMethod);
+                if (strpos($immediateCallerAndMethod, '::') === false) {
+                    continue;
+                }
+
+                [$callerClass, $methodName] = explode('::', $immediateCallerAndMethod); // @phpstan-ignore offsetAccess.notFound
 
                 if (
                     $methodName === $calledMethodName

src/Rule/ForbidNotNormalizedTypeRule.php

@@ -520,7 +520,7 @@ private function processMultiTypePhpParserNode(
         foreach ($innerTypeNodes as $i => $iValue) {
             for ($j = $i + 1; $j < $countOfNodeTypes; $j++) {
                 $typeNodeA = $iValue;
-                $typeNodeB = $innerTypeNodes[$j];
+                $typeNodeB = $innerTypeNodes[$j]; // @phpstan-ignore offsetAccess.notFound
 
                 $typeA = $scope->getFunctionType($typeNodeA, false, false);
                 $typeB = $scope->getFunctionType($typeNodeB, false, false);
@@ -588,7 +588,7 @@ private function processMultiTypePhpDocNode(
         foreach ($innerTypeNodes as $i => $iValue) {
             for ($j = $i + 1; $j < $countOfNodeTypes; $j++) {
                 $typeNodeA = $iValue;
-                $typeNodeB = $innerTypeNodes[$j];
+                $typeNodeB = $innerTypeNodes[$j]; // @phpstan-ignore offsetAccess.notFound
 
                 $typeA = $this->typeNodeResolver->resolve($typeNodeA, $nameSpace);
                 $typeB = $this->typeNodeResolver->resolve($typeNodeB, $nameSpace);

src/Visitor/ClassPropertyAssignmentVisitor.php

@@ -8,15 +8,15 @@
 use PhpParser\Node\Expr\StaticPropertyFetch;
 use PhpParser\NodeVisitorAbstract;
 use function array_pop;
-use function count;
+use function end;
 
 class ClassPropertyAssignmentVisitor extends NodeVisitorAbstract
 {
 
     public const ASSIGNED_EXPR = ShipMonkNodeVisitor::NODE_ATTRIBUTE_PREFIX . 'assignment';
 
     /**
-     * @var Node[]
+     * @var list<Node>
      */
     private array $stack = [];
 
@@ -33,7 +33,7 @@ public function beforeTraverse(array $nodes): ?array
     public function enterNode(Node $node): ?Node
     {
         if ($this->stack !== []) {
-            $parent = $this->stack[count($this->stack) - 1];
+            $parent = end($this->stack);
 
             if (
                 $parent instanceof Assign

src/Visitor/TopLevelConstructorPropertyFetchMarkingVisitor.php

@@ -17,7 +17,7 @@ class TopLevelConstructorPropertyFetchMarkingVisitor extends NodeVisitorAbstract
     public const IS_TOP_LEVEL_CONSTRUCTOR_FETCH_ASSIGNMENT = ShipMonkNodeVisitor::NODE_ATTRIBUTE_PREFIX . 'topLevelConstructorFetchAssignment';
 
     /**
-     * @var Node[]
+     * @var list<Node>
      */
     private array $stack = [];
 
@@ -38,9 +38,9 @@ public function enterNode(Node $node): ?Node
         if (
             $nodesInStack >= 3
             && $node instanceof PropertyFetch
-            && $this->stack[$nodesInStack - 1] instanceof Assign
-            && $this->stack[$nodesInStack - 2] instanceof Expression
-            && $this->stack[$nodesInStack - 3] instanceof ClassMethod
+            && $this->stack[$nodesInStack - 1] instanceof Assign // @phpstan-ignore offsetAccess.notFound
+            && $this->stack[$nodesInStack - 2] instanceof Expression // @phpstan-ignore offsetAccess.notFound
+            && $this->stack[$nodesInStack - 3] instanceof ClassMethod // @phpstan-ignore offsetAccess.notFound
             && $this->stack[$nodesInStack - 3]->name->name === '__construct'
         ) {
             $node->setAttribute(self::IS_TOP_LEVEL_CONSTRUCTOR_FETCH_ASSIGNMENT, true);

src/Visitor/UnusedExceptionVisitor.php

@@ -19,15 +19,15 @@
 use PhpParser\Node\Stmt\Throw_;
 use PhpParser\NodeVisitorAbstract;
 use function array_pop;
-use function count;
+use function end;
 
 class UnusedExceptionVisitor extends NodeVisitorAbstract
 {
 
     public const RESULT_USED = ShipMonkNodeVisitor::NODE_ATTRIBUTE_PREFIX . 'resultUsed';
 
     /**
-     * @var Node[]
+     * @var list<Node>
      */
     private array $stack = [];
 
@@ -44,7 +44,7 @@ public function beforeTraverse(array $nodes): ?array
     public function enterNode(Node $node): ?Node
     {
         if ($this->stack !== []) {
-            $parent = $this->stack[count($this->stack) - 1];
+            $parent = end($this->stack);
 
             if ($this->isNodeInInterest($node) && $this->isUsed($parent)) {
                 $node->setAttribute(self::RESULT_USED, true);